Developing public health regulations for marijuana: lessons from alcohol and tobacco

The burden of disease attributable to cannabis use in Canada in 2012

BACKGROUND AND AIMS

Cannabis use is associated with several adverse health effects. However, little is known about the cannabis-attributable burden of disease. This study quantified the age-, sex- and adverse health effect-specific cannabis-attributable (1) mortality, (2) years of life lost due to premature mortality (YLLs), (3) years of life lost due to disability (YLDs) and (4) disability-adjusted life years (DALYs) in Canada in 2012.

DESIGN

Epidemiological modeling.

SETTING

Canada.

PARTICIPANTS

Canadians aged ≥ 15 years in 2012.

MEASUREMENTS

Using comparative risk assessment methodology, cannabis-attributable fractions were computed using Canadian exposure data and risk relations from large studies or meta-analyses. Outcome data were obtained from Canadian databases and the World Health Organization. The 95% confidence intervals (CIs) were computed using Monte Carlo methodology.

FINDINGS

Cannabis use was estimated to have caused 287 deaths (95% CI = 108, 609), 10,533 YLLs (95% CI = 4760, 20,833), 55,813 YLDs (95% CI = 38,175, 74,094) and 66,346 DALYs (95% CI = 47,785, 87,207), based on causal impacts on cannabis use disorders, schizophrenia, lung cancer and road traffic injuries. Cannabis-attributable burden of disease was highest among young people, and males accounted for twice the burden than females. Cannabis use disorders were the most important single cause of the cannabis-attributable burden of disease.

CONCLUSIONS

The cannabis-attributable burden of disease in Canada in 2012 included 55,813 years of life lost due to disability, caused mainly by cannabis use disorders. Although the cannabis-attributable burden of disease was substantial, it was much lower compared with other commonly used legal and illegal substances. Moreover, the evidence base for cannabis-attributable harms was smaller.

A common public health-oriented policy framework for cannabis, alcohol and tobacco in Canada?

Support for a public health approach to cannabis policy as an alternative to prohibition and criminalization is gaining momentum. Recent drug policy changes in the United States suggest growing political feasibility for legal regulation of cannabis in other North American jurisdictions. This commentary discusses the outcomes of an interdisciplinary policy meeting with Canadian experts and knowledge users in the area of substance use interventions. The meeting explored possibilities for applying cross-substance learning on policy interventions for alcohol, tobacco and cannabis, towards the goal of advancing a public health framework for reducing harms associated with substance use in Canada. The meeting also explored how the shift in approach to cannabis policy can provide an opportunity to explore potential changes in substance use policy more generally, especially in relation to tobacco and alcohol as legally regulated substances associated with a heavy burden of illness. Drawing from the contributions and debates arising from the policy meeting, this commentary identifies underlying principles and opportunities for learning from policy interventions across tobacco, alcohol and cannabis, as well as research gaps that need to be addressed before a public health framework can be effectively pursued across these substances.

Crude estimates of cannabis-attributable mortality and morbidity in Canada-implications for public health focused intervention priorities

BACKGROUND

Cannabis is the most commonly used drug in Canada; while its use is currently controlled by criminal prohibition, debates about potential control reforms are intensifying. There is substantive evidence about cannabis-related risks to health in various key outcome domains; however, little is known about the actual extent of these harms specifically in Canada.

METHODS

Based on epidemiological data (e.g. prevalence of relevant cannabis use rates and relevant risk behaviors; risk ratios; and annual numbers of morbidity/mortality cases in relevant domains), and applying the methodology of comparative risk assessment, we estimated attributable fractions for cannabis-related morbidity and mortality, specifically for: (i) motor-vehicle accidents (MVAs); (ii) use disorders; (iii) mental health (psychosis) and (iv) lung cancer.

RESULTS

MVAs and lung cancer are the only domains where cannabis-attributable mortality is estimated to occur. While cannabis use results in morbidity in all domains, MVAs and use disorders by far outweigh the other domains in the number of cases; the popularly debated mental health consequences (e.g., psychosis) translate into relatively small case numbers.

CONCLUSIONS

The present crude estimates should guide and help prioritize public health-oriented interventions for the cannabis-related health burden in the population in Canada; formal burden of disease calculations should be conducted.

Correlates of Amount Spent on Marijuana Buds During a Discrete Purchase at Medical Marijuana Dispensaries: Results from a Pilot Study

Marijuana purchasing behaviors vary by the purchaser's individual characteristics; however, little is known about patients' purchasing behaviors when buying from medical marijuana dispensaries (MMDs). Our objective was to explore whether patient characteristics were associated with amount spent during one financial transaction at medical marijuana dispensaries. We conducted a pilot study of four purposively sampled MMD locations in Long Beach, California, in 2012. A total of 132 medical marijuana patients (33 patients per dispensary) participated in an exit survey about their demographic characteristics, conditions for their medical marijuana recommendation, amount spent at the dispensary, and cross-streets of where they lived. The sample reported amounts spent on discrete purchases of marijuana buds averaging $40.82 (ranging from $10 to $255). Multivariate regression analyses indicated average amount spent differed significantly by patient age and condition. An increase in 10 years of age was associated with a 10% higher amount spent. Receiving a recommendation for anxiety and/or sleeping problems or other nonspecified conditions was related to higher discrete purchase amounts than chronic pain. This pilot suggests that variations in patient purchasing behaviors from MMDs exist. These purchase behaviors can provide insight into variations in how patients use dispensaries, consume products, and allocate personal resources.

Prevalence of Marijuana Use Disorders in the United States Between 2001-2002 and 2012-2013

IMPORTANCE

Laws and attitudes toward marijuana in the United States are becoming more permissive but little is known about whether the prevalence rates of marijuana use and marijuana use disorders have changed in the 21st century.

OBJECTIVE

To present nationally representative information on the past-year prevalence rates of marijuana use, marijuana use disorder, and marijuana use disorder among marijuana users in the US adult general population and whether this has changed between 2001-2002 and 2012-2013.

DESIGN, SETTING, AND PARTICIPANTS

Face-to-face interviews conducted in surveys of 2 nationally representative samples of US adults: the National Epidemiologic Survey on Alcohol and Related Conditions (data collected April 2001-April 2002; N = 43,093) and the National Epidemiologic Survey on Alcohol and Related Conditions-III (data collected April 2012-June 2013; N = 36,309). Data were analyzed March through May 2015.

MAIN OUTCOMES AND MEASURES

Past-year marijuana use and DSM-IV marijuana use disorder (abuse or dependence).

RESULTS

The past-year prevalence of marijuana use was 4.1% (SE, 0.15) in 2001-2002 and 9.5% (SE, 0.27) in 2012-2013, a significant increase (P < .05). Significant increases were also found across demographic subgroups (sex, age, race/ethnicity, education, marital status, income, urban/rural, and region). The past-year prevalence of DSM-IV marijuana use disorder was 1.5% (0.08) in 2001-2002 and 2.9% (SE, 0.13) in 2012-2013 (P < .05). With few exceptions, increases in the prevalence of marijuana use disorder between 2001-2002 and 2012-2013 were also statistically significant (P < .05) across demographic subgroups. However, the prevalence of marijuana use disorder among marijuana users decreased significantly from 2001-2002 (35.6%; SE, 1.37) to 2012-2013 (30.6%; SE, 1.04).

CONCLUSIONS AND RELEVANCE

The prevalence of marijuana use more than doubled between 2001-2002 and 2012-2013, and there was a large increase in marijuana use disorders during that time. While not all marijuana users experience problems, nearly 3 of 10 marijuana users manifested a marijuana use disorder in 2012-2013. Because the risk for marijuana use disorder did not increase among users, the increase in prevalence of marijuana use disorder is owing to an increase in prevalence of users in the US adult population. Given changing laws and attitudes toward marijuana, a balanced presentation of the likelihood of adverse consequences of marijuana use to policy makers, professionals, and the public is needed.

The Public Health Framework of Legalized Marijuana in Colorado

On January 1, 2014, Colorado became the first state in the nation to sell legal recreational marijuana for adult use. As a result, Colorado has had to carefully examine potential population health and safety impacts as well as the role of public health in response to legalization. We have discussed an emerging public health framework for legalized recreational marijuana. We have outlined this framework according to the core public health functions of assessment, policy development, and assurance. In addition, we have discussed challenges to implementing this framework that other states considering legalization may face.

Cannabis vaping and public health--some comments on relevance and implications

Cannabis-vaping entails relevant but probably varied effects for public health: it may reduce certain cannabis use-related health risks, but entice cannabis-naive individuals into use due to "cleaner" imagery. Improved evidence is needed to guide informed and differentiated policies for cannabis-vaping, which emphasizes the urgent need for public health-based cannabis regulation.

Past 15-year trends in adolescent marijuana use: Differences by race/ethnicity and sex

BACKGROUND

The potential for increases in adolescent marijuana use is an important concern given recent changes in marijuana policy. The purpose of this study was to estimate trends in marijuana use from 1999 to 2013 among a national sample of US high school students. We examine changes over time by race/ethnicity and sex.

METHODS

Data are from the National Youth Risk Behavior Survey (YRBS), which involves biennial, school-based surveys that generate nationally representative data about 9th-12th grade students in the United States. Students self-reported sex, race/ethnicity, and marijuana use (i.e., lifetime use, past 30-day use, any use before age 13). We generated national estimates of the prevalence of marijuana use for the time period, and also tested for linear and quadratic trends (n=115,379).

RESULTS

The prevalence of lifetime marijuana use decreased modestly from 1999 to 2009 (44% to 37%), and has increased slightly since 2009 (41%). Other marijuana use variables (e.g., past 30-day use) followed a similar pattern over time. The prevalence of past 30-day use from 1999 to 2013 for all groups and both sexes was 22.5%, and it was lowest among Asians and highest among American Indian/Alaska Natives. Although boys have historically had a higher prevalence of marijuana use, results indicate that male-female differences in marijuana use decreased over time.

CONCLUSION

Despite considerable changes in state marijuana policies over the past 15 years, marijuana use among high school students has largely declined. Continued surveillance is needed to assess the impact of policy changes on adolescent marijuana use.

Assessing the public health impacts of legalizing recreational cannabis use in the USA

A major challenge in assessing the public health impact of legalizing cannabis use in Colorado and Washington State is the absence of any experience with legal cannabis markets. The Netherlands created a de facto legalized cannabis market for recreational use, but policy analysts disagree about how it has affected rates of cannabis use. Some US states have created de facto legal supply of cannabis for medical use. So far this policy does not appear to have increased cannabis use or cannabis-related harm. Given experience with more liberal alcohol policies, the legalization of recreational cannabis use is likely to increase use among current users. It is also likely that legalization will increase the number of new users among young adults but it remains uncertain how many may be recruited, within what time frame, among which groups within the population, and how many of these new users will become regular users.

Medical marijuana programs - Why might they matter for public health and why should we better understand their impacts?

Objective

Although cannabis is an illegal drug, ‘medical marijuana programs’ (MMPs) have proliferated (e.g., in Canada and several US states), allowing for legal cannabis use for therapeutic purposes. While both health risks and potential therapeutic benefits for cannabis use have been documented, potential public health impacts of MMPs — also vis-à-vis other psychoactive substance use — remain under-explored.

Methods

We briefly reviewed the emerging evidence on MMP participants' health status, and specifically other psychoactive substance use behaviors and outcomes.

Results

While data are limited in amount and quality, MMP participants report improvements in overall health status, and specifically reductions in levels of risky alcohol, prescription drug and — to some extent — tobacco or other illicit drug use; at the same time, increases in cannabis use and risk/problem patterns may occur.

Conclusion

MMP participation may positively impact — for example, by way of possible ‘substitution effects’ from cannabis use — other psychoactive substance use and risk patterns at a scale relevant for public health, also influenced by the increasing population coverage of MMPs. Yet, net overall MMP-related population health effects need to be more rigorously and comprehensively assessed, including potential increases in cannabis use related risks and harms.

Medical Marijuana programs: implications for cannabis control policy--observations from Canada

While prohibition has been the dominant regime of cannabis control in most countries for decades, an increasing number of countries have been implementing cannabis control reforms recently, including decriminalization or even legalization frameworks. Canada has held out from this trend, although it has among the highest cannabis use rates in the world. Cannabis use is universally criminalized, and the current (conservative) federal government has vowed not to implement any softening reforms to cannabis control. As a result of several higher court decisions, the then federal government was forced to implement a 'medical marijuana access regulations' program in 2001 to allow severely ill patients therapeutic use and access to therapeutic cannabis while shielding them from prosecution. The program's regulations and approval processes were complex and subject to extensive criticism; initial uptake was low and most medical marijuana users continued their use and supply outside the program's auspices. This year, the government introduced new 'marijuana for medical purposes regulations', which allow physicians to 'authorize' medical marijuana use for virtually any health condition for which this is considered beneficial; supply is facilitated by licensed commercial producers. It is expected that some 500,000 users, and dozens of commercial producers will soon be approved under the program, arguably constituting - as with medical marijuana schemes elsewhere, e.g. in California--de facto 'legalization'. We discuss the question whether the evolving scope and realities of 'medical cannabis' provisions in Canada offer a 'sneaky side door' or a 'better third way' to cannabis control reform, and what the potential wider implications are of these developments.

Investigating the intersection of policing and public health

In an accompanying Perspective, Scott Burris and Stephen Koester discuss the association between punitive policies and health inequalities and argue for more research focusing on policing and health. Please see later in the article for the Editors' Summary